NIOSH updates manual for Lifting Equation
NIOSH recently published an updated version of its Revised NIOSH Lifting Equation (RNLE) Manual. The agency says the essential contents have not changed, rather graphics and tables have been improved, identified typographical errors have been corrected, and the document has been reformatted to be searchable.
NIOSH states that the most notable typographical correction replaces a recovery time factor of 1.2 which was used to determine the short duration lifting tasks (on pages 23 and 24 of the 1994 manual). The subsequently calculated recovery time on page 24 is corrected to 30 minutes from 36 minutes. The new recovery time factor of 1.0 and revised recovery time of 30 minutes are now used throughout the new version.
Additionally, alternative text for all figures and equations have been added in compliance of Section 508, which requires agencies to make their electronic information accessible to people with disabilities.
What is the NIOSH Lifting Equation?
One of the most utilized resources for determining safe lifting limits is the National Institute for Occupational Safety and Health (NIOSH) Lifting Equation. The NIOSH equation sets a fixed weight of 51 pounds as the load constant (that is generally considered the maximum load nearly all healthy workers should be able to lift under optimal conditions.)
However, the NIOSH equation also uses other factors such as height and angle of the lift, frequency of the lift, type of hand grip, and travel distance; these are all as important in assessing a lift as the weight of the object.
The final product of using the NIOSH Lifting Equation is a Recommended Weight Limit (RWL) for a task, given all the factors. Note: The NIOSH Lifting Equation is not suitable for one-handed lifts, or to unstable loads.